Abstract: Disclosed are solid oxide fuel cell systems, and methods for reducing temperature distribution across electrolytes within solid oxide fuel cells (SOFC), and increasing overall system efficiency. In one embodiment, the SOFCs include preheating channels that are interposed between electrolyte electrode assemblies within SOFCs, to provide internal heat exchange. The fuel and/or air entering the SOFC can be preheated in the preheating channels, thereby reducing or eliminating the need for an external preheating system. The preheating channels also provide barriers between each electrolyte electrode assembly, which aids in isolating damage within a single fuel cell.